Scag Power Equipment STT User manual

MODEL STT
THIS MANUAL CONTAINS THE OPERATING
INSTRUCTIONS AND SAFETY INFORMA-
TION FOR YOUR SCAG MOWER. READING
THIS MANUAL CAN PROVIDE YOU WITH
ASSISTANCE IN MAINTENANCE AND AD-
JUSTMENT PROCEDURES TO KEEP YOUR
MOWER PERFORMING TO MAXIMUM EFFI-
CIENCY. THE SPECIFIC MODELS THAT THIS
BOOK COVERS ARE CONTAINED ON THE
INSIDE COVER. BEFORE OPERATING YOUR
MACHINE, PLEASE READ ALL THE INFOR-
MATION ENCLOSED.
PART NUMBER 03059
OPERATOR’S MANUAL

FAILURE TO FOLLOW SAFE OPERATING PRACTICES
MAY RESULT IN SERIOUS INJURY.
* Keep all shields in place, especially the grass discharge chute.
* Before performing any maintenance or service, stop the machine and
remove the spark plug wire and ignition key.
* If a mechanism becomes clogged, stop the engine before cleaning.
* Keep hands, feet and clothing away from power-driven parts.
* Read this manual completely as well as other manuals that came
with your mower.
* Keep others off the tractor only one person at a time)
REMEMBER - YOUR MOWER IS ONLY AS SAFE AS THE OPERATOR!
Hazard control and accident prevention are dependent upon the awareness,
concern, prudence, and proper training of the personnel involved in the
operation, transport, maintenance, and storage of the equipment.
WARNING:
Always use the entire serial number listed on the serial number
tag when referring to this product.
This manual covers the operating instructions
and illustrated parts list for:
STT52-22CH with a se ial numbe of 4260001- 4269999
STT52B-22CH with a se ial numbe of 4280001- 4289999
STT61-22CH with a se ial numbe of 4270001- 4279999
STT61B-22CH with a se ial numbe of 4290001- 4299999
STT52-25CH with a se ial numbe of 4300001- 4309999
STT61-25CH with a se ial numbe of 4310001- 4319999
STT52B-25CH with a se ial numbe of 4320001- 4329999
STT61B-25CH with a se ial numbe of 4330001- 4339999
STT52-22KA with a se ial numbe of 4340001- 4349999
STT61-22KA with a se ial numbe of 4350001- 4359999
STT52B-22KA with a se ial numbe of 4360001- 4369999
STT61B-22KA with a se ial numbe of 4370001- 4379999

1
GENERAL INFORMATION
1.1 INTRODUCTION
Your mower was built to the highest standards in the
industry. However, the prolonged life and maximum
efficiency of your mower depends on you following the
operating, maintenance and adjustment instructions in
this manual.
If additional information or service is needed, contact
your Scag Power quipment Dealer.
We encourage you to contact your dealer for repairs. All
Scag dealers are informed of the latest methods to service
this equipment and provide prompt and efficient service
in the field or at their service shop. They carry a full line
of Scag service parts.
USE OF OTHER THAN ORIGINAL SCAG
REPLACEMENT PARTS WILL VOID THE
WARRANTY.
When ordering parts, always give the model and serial
number of your tractor. The serial number plate is
located where shown in Figures 1-1.
For pictorial clarity, some illustrations and figures in this
manual may show shields, guards or plates open or
removed. Under no circumstances should your mower be
operated without these devices in place.
All information i ba ed upon product information
available at the time of approval for printing. Scag
Power Equipment re erve the right to make change
at any time without notice and without incurring any
obligation.
1.2 DIRECTION REFERENCE
The Right and Left, Front and Rear of the
machine are referenced from the operators right and left
when seated in the normal operating position and facing
the forward travel direction.
1.3 SERVICING THE ENGINE AND DRIVE
TRAIN COMPONENTS
The detail servicing and repair of the engine, hydraulic
pumps and gearboxes are not covered in this manual;
only routine maintenance and general service instructions
are provided. For service of these components during the
limited warranty period, it is important to contact your
Scag dealer or find a local authorized servicing agent of
the component manufacturer. Any unauthorized work
done on these components during the warranty period
may void your warranty.
Section 1
Figure 1-1 Tractor Serial Number Plate Location
390S0137
SERIAL NUMBER
PLATE LOCATION
R
MODEL
SERIAL
Division of Metalcraft of Mayville, Inc.
Mayville, Wisconsin 53050
Patents Issued and Pending
MANUFACTURED UNDER ONE OR MORE
OF THE FOLLOWING PATENTS:
PATENTS PENDING
4,487,006
4,885,903
4,920,733
4,967,543
4,991,382
4,998,948
4,118,617

2
SAFETY INFORMATION
2.1 INTRODUCTION
Your mower is only as safe as the operator. Carelessness
or operator error may result in serious bodily injury or
death. Hazard control and accident prevention are
dependent upon the awareness, concern, prudence, and
proper training of the personnel involved in the operation,
transport, maintenance and storage of the equipment.
Make sure every operator is properly trained and
thoroughly familiar with all of the controls before
operating the mower.
READ THIS OPERATORS MANUAL BEFORE
ATTEMPTING TO START YOUR MOWER.
A replacement manual is available from your authorized
Scag Service Dealer or by contacting Scag Power
quipment, Service Department at P.O. Box 152,
Mayville, WI 53050. Please indicate the complete model
and serial number of your Scag product when requesting
replacement manuals.
2.2 SIGNAL WORDS
This symbol means Attention! Become Alert! Your
Safety i Involved!" The symbol is used with the
following signal words to attract your attention to safety
messages found on the decals on the machine and
throughout this manual. The message that follows the
symbol contains important information about safety. To
avoid injury and possible death, carefully read the
message! Be sure to fully understand the causes of
possible injury or death.
Signal Word:
It is a distinctive word found on the safety decals on the
machine and throughout this manual that alerts the
viewer to the existence and relative degree of the hazard.
The signal word WARNING denotes that a hazard
exists on or near the machine that can result in injury or
death if proper precautions are not taken.
The signal word DANG R denotes that an extremely
hazardous situation exists on or near the machine that
could result in high probability of death or irreparable
injury if proper precautions are not taken.
CAUTION:
The signal word CAUTION is a reminder of safety
practices on or near the machine that could result in
personal injury if proper precautions are not taken.
Your safety and the safety of others depends significantly
upon your knowledge and understanding of all correct
operating practices and procedures of this machine.
2.3 BEFORE OPERATION
CONSIDERATIONS
1. NEVER allow children to operate this riding mower.
Do not allow adults to operate this machine without
proper instructions.
2. DO NOT mow when children and/or others are
present.
3. Clear the area to be mowed of objects that could be
picked up and thrown by the cutter blades.
4. DO NOT carry passengers.
WARNING:
Section 2

3
10. DO NOT add fuel to a running or hot engine. Allow
the engine to cool for several minutes before adding
fuel.
11. Keep flammable objects (cigarettes, matches, etc.),
open flames and sparks away from the fuel tank and
fuel container.
12. quipment must comply with the latest requirements
per SA J137 and/or ANSI/ASA S279 when driven
on public roads.
If the mower is driven on public roads, it must
comply with state and local ordinances as well as
SAE J137 and/or A SI / ASAE S279 requirements.
Contact your local authorities for regulations and
equipment requirements.
13. DO NOT operate without the side discharge chute
installed and in the down position.
14. Check the blade mounting bolts at frequent intervals
for proper tightness.
15. Make sure all hydraulic fluid connections are tight
and all hydraulic hoses and lines are in good
condition before starting the machine.
2.4 OPERATION CONSIDERATIONS
1. Know the function of all controls and how to stop
quickly.
2. Reduce speed and exercise extreme caution on slopes
and in sharp turns to prevent tipping or loss of
control. Be especially cautious when changing
directions on slopes.
DO NOT operate on steep slopes. To check a
slope, attempt to back up it (with the cutter deck
down). If the machine can back up the slope
without the wheels slipping, reduce speed and use
extreme caution. ALWAYS FOLLOW OSHA
APPROVED OPERATION.
6. Operator hearing protection is recommended,
particularly for continuous operation of the mower.
Wear suitable hearing protection. Prolonged
exposure to loud noise can cause hearing
impairment or loss.
7. Keep the machine and attachments in good
operating condition. Keep all shields and safety
devices in place. If a shield, safety device or decal
is defective or damaged, repair or replace it before
operating the machine.
This machine is equipped with an interlock
system intended to protect the operator and
others from injury. This is accomplished by
2.3 BEFORE OPERATION
CONSIDERATIONS (CONT'D)
5. DO NOT wear loose fitting clothing that could get
tangled in moving parts. Do not operate the machine
wearing shorts; always wear adequate protective
clothing including long pants. Wearing safety
glasses, safety shoes and a helmet is advisable and is
required by some local ordinances and insurance
regulations.
Section 2
WARNING:
preventing the engine from starting unless the
deck drive is disengaged, the parking brake is on,
the steering control levers are in the neutral
position and the operator is in the seat. The
system shuts off the engine if the operator leaves
the seat with the deck drive engaged and/or the
steering control levers are not in the neutral
postion and the parking brake is not engaged.
Never operate equipment with the interlock system
disconnected or malfunctioning.
8. Be sure the interlock switches are functioning
correctly.
9. Fuel is flammable; handle it with care. Fill the fuel
tank outdoors. Never fill it indoors. Use a funnel or
spout to prevent spillage. Clean up any spillage
before starting the engine.
-NOTE-
WARNING:

4
Section 2
2.4 OPERATION CONSIDERATIONS
(CONT'D)
3. To prevent tipping or loss of control, do not start or
stop suddenly, avoid unnecessary turns and travel at
reduced speed.
4. When using any attachment, never direct the
discharge of material toward bystanders or allow
anyone near the machine while in operation.
5. Before attempting to start the engine, with the
operator in the seat, disengage power to the cutter
deck, place the steering control levers in the neutral
position and engage the parking brake.
6. If the mower discharge ever plugs, shut off the
engine, remove the ignition key, and wait for all
movement to stop before removing the obstruction.
Do not use your hand to dislodge the clogged
discharge chute. Use a stick or other device to
remove clogged material.
7. Be alert for holes, rocks, roots and other hidden
hazards in the terrain. Keep away from any dropoff.
Beware of overhead obstructions (low limbs, etc.),
underground obstacles (sprinklers, pipes, tree roots,
etc.). Cautiously enter a new area. Be alert for
hidden hazards.
8. Disengage power to cutter deck before backing up.
Do not mow in reverse unless absolutely necessary
and then only after observation of the entire area
behind the mower.
9. DO NOT turn sharply. Use care when backing up.
10. Disengage power to cutter deck before crossing
roads, walks or gravel drives.
11. Mow only in daylight or good artificial light.
12. Take all possible precautions when leaving the
machine unattended, such as disengaging the mower,
lowering the attachments, setting the parking brake,
stopping the engine, and removing the key.
13. Disengage power to the attachments when
transporting or when not in use.
14. The machine and attachments should be stopped and
inspected for damage after striking a foreign object,
and damage should be repaired before restarting and
operating the machine.
15. DO NOT touch the engine or the muffler while the
engine is running or immediately after stopping.
These areas may be hot enough to cause a burn.
16. DO NOT run the engine inside a building or a
confined area without proper ventilation. xhaust
fumes are hazardous and could cause death.
2.5 MAINTENANCE CONSIDERATIONS
1. Never make adjustments to the machine with the
engine running unless specifically instructed to do so.
If the engine is running, keep hands, feet, and
clothing away from moving parts.
2. Remove the key from the ignition switch to prevent
accidental starting of the engine when servicing or
adjusting the machine.
3. Keep all nuts, bolts and screws tight, to ensure the
machine is in safe working condition. Check blade
mounting bolts frequently to be sure they are tight.
4. Do not change the engine governor settings or
overspeed the engine. See the engine operator's
manual for information on engine settings.
5. To reduce fire hazard, keep the engine free of grass,
leaves, excessive grease, oil and dirt.
6. Hydraulic fluid i under high pre ure. Keep body
and hands away from pinholes or nozzles that eject
hydraulic fluid under high pressure. If you need
service on your hydraulic system, please see your
authorized Scag dealer.
7. Hydraulic fluid under high pressure may have
sufficient force to penetrate skin and cause serious
injury. If hydraulic fluid is injected into the skin, it
must be surgically removed within a few hours by a
doctor or gangrene may result.

5
Section 2
2.6 SAFETY AND INSTRUCTIONAL DECALS
DANGER
SPINNING BLADE
KEEP CLEAR
CONTACT CAN INJURE
48071
ROTATING BLADES AND BELTS
WARNING
KEEP HANDS, FEET & CLOTHING CLEAR
KEEP ALL GUARDS IN PLACE
SHUT OFF ENGINE & DISENGAGE BLADE
CLUTCH BEFORE SERVICING
CLEAR AREA OF DEBRIS BEFORE MOWING
USE CAUTION IN DIRECTING DISCHARGE
KEEP BYSTANDERS, CHILDREN & PETS AWAY
READ INSTRUCTION MANUAL BEFORE OPERATING
DO NOT OPERATE WITHOUT DISCHARGE CHUTE, MULCHING
KIT, OR ENTIRE GRASS CATCHER INSTALLED
481040
WARNING
INSTALL BELT COVER BEFORE
OPERATING MACHINE
READ OPERATOR'S MANUAL
481039
CAUTION
AVOID INJURY FROM
BURNS. SHUT OFF
ENGINE BEFORE
REMOVING FUEL
TANK CAP.
481272
390S0150
CAUTION
KEEP BYSTANDERS AWAY
CAUTION
BEFORE OPERATING
READ OPERATOR'S
MANUAL AND SAFETY
INSTRUCTIONS
481567
START / DRIVE
PROCEDURE
ENGAGE PARKING BRAKE
DISENGAGE MOWER DECK DRIVE
MOVE CONTROL HANDLES
TO NEUTRAL LOCK POSITION
START ENGINE
RELEASE PARKING BRAKE
SELECT FORWARD OR
REVERSE SPEED WITH
HYDRO CONTROL HANDLES
481568
FORWARD
REVERSE
FR
IMPORTANT ADJUSTMENT
PROCEDURES
READ OPERATOR'S MANUAL
FOR MORE DETAILS
NEUTRAL ADJUSTMENT
TRACKING ADJUSTMENT
FREE WHEEL OPERATION
HYDRAULIC TANK FLUID LEVEL
Check tire pressure-
(Drive tires - 12 psi,
Caster tires - 25 psi)
To move machine without running
the engine, rotate both dump valve
levers located at the LH side of
the pumps CCW 1/2 turn to
"freewheel" positions. Return
levers to original position to
operate the mower.
If the machine pulls to the right,
adjust LH control linkage CCW to
slow left wheel. If the machine
pulls to the left, adjust RH control
linkage CCW to slow right wheel.
Readjust neutral if necessary.
With an operator in the seat,
engine running, control levers
in neutral and the parking brake
disengaged - adjust control
linkage. Loosen jam nuts. If wheel
rotates forward, adjust turnbuckle
CCW. If wheel rotates rearward,
adjust turnbuckle CW. Adjust until
drive wheel stops turning. Tighten
jam nuts. Repeat for opposite side.
Check hydraulic fluid level
daily while fluid is cool.
Fluid level should be 3-1/4"
below top of filler neck.
Fill with SAE 20W50 motor oil only.
IMPORTANT!:
Do not overfill. Room for hot
fluid expansion must be allowed
or resulting expansion may cause
leaks in the system.
Gearbox lubricant:
SAE 80W90 gear oil
481588
Loosen jam nuts
Rotate turnbuckle

6
SPECIFICATIONS
Section 3
3.1 ENGINE
General Type ............................................................................. Heavy Duty Industrial/Commercial Gasoline
Brand ......................................................................................... Kohler, 22HP Spec. #PS-76510) 25HP Spec. #PS-68579)
Kawasaki, 22HP Spec. # FD661D-AS0201)
Model ......................................................................................... Kohler Command, Kawasaki FD661D
Horsepower ................................................................................ 22 HP at 3600 RPM Model STT52&52b-22CH, STT61&61B-22CH)
25 HP at 3600 RPM Model STT52&52B-25CH, STT61&61B-25CH)
22 HP at 3600 RPM Model STT52&52B-22KA, STT61&61B-22KA)
Type ........................................................................................... 4 Cycle Gasoline, Twin Cylinder, Horizontal Shaft
Displacement ............................................................................ 22HP Kohler 674 cc., 25HP Kohler 725cc., 22HP Kawasaki 617cc
Cylinders ................................................................................... 2 with Cast Iron Sleeves
Governor .................................................................................... Mechanical Type with Variable Speed Control Set At 3600 RPM
Idle Speed .................................................................................. 1400 RPM
Kohler Fuel Pump Group .......................................................... Mechanical Type Fuel Pump with In-Line Fuel Filter, Fixed Jet
Carburetor with Smart-Choke and Fuel Shutdown Solenoid
Kawasaki Fuel Pump Group ..................................................... Electric Fuel Pump with In-Line Fuel Filter,Fixed Jet Downdraft
Carburetor.
Fuel ............................................................................................ Non-Leaded Gasoline with a Minimum Octane Rating of 87
Oil Pump Group ........................................................................ Positive Displacement Gerotor Oil Pump with Remote Oil
Filter
Starter ........................................................................................ Electric Starting with Solenoid Shift Starter
Belts: .......................................................................................... Kevlar cord. Self-adjusting, Self-tightening
Deck Drive Belt ..................................................................... Scag Part Number - 481460
Pump Drive Belt .................................................................... Scag Part Number - 481461
Kawasaki Fan Belt .................................................................. Part Number - Mitsubishi 59011-2056 N/A Through Scag)
3.2 ELECTRICAL
Battery ....................................................................................... 12 Volt
Charging System ....................................................................... Alternator
Charging Output ....................................................................... 12 Volt, 15 Amp
System Polarity .......................................................................... Negative Ground
Starter ........................................................................................ 12 Volt Electric Ring Gear Type, Key and Solenoid Operated
Interlock Switches ..................................................................... Seat, Neutral Control, Mower Engagement BBC), Parking Brake
Instrument Panel ....................................................................... Ammeter, Hourmeter, Key Switch, Throttle Lever, Manual Choke,
BBC Switch, Fuses and Safety Start module, Temp. gauge KA)
Fuses .......................................................................................... Two 2) 20 Amp
3.3TRACTOR
Drive System ............................................................................. Hydraulic Drive with Two Variable Displacement Pumps and Two
Cast-iron High Torque Motors
Hydrostatic Pumps ..................................................................... Two Hydro-Gear BDP 10L Pumps with Dump Valves for
movement without running the engine
Drive Wheel Motors .................................................................. Two Ross Model MB 15 cu. inch Cast-iron High Torque Motors
Steering/Travel Control ............................................................. Twin Lever Fingertip Steering Control with Individual Control to
Each Wheel with Gas Spring Dampers
Parking Brake ............................................................................ Lever Actuated Linkage to Brakes on Both Drive Wheel Axles
Wheels:
2) Front Caster .................................................................... 13 X 5.00 Four-Ply
2) Drive ................................................................................. 23 X 10.5 X 12 Four-Ply Pneumatic Tubeless, Radius Edge, 52"
................................................................................................... 24X12.0X12.0 Four-Ply Pneumatic Tubeless, Radius Edge, 61"
Fuel Tank ................................................................................... 10-Gallon Seamless Polyethylene Tank with Fuel Gauge Fill Cap
Tire Pressure:
Front Caster.......................................................................... 25 PSI
Drive ..................................................................................... 12 PSI
Seat ............................................................................................ Padded, Thick Cushion with Extra Spring Support

7
3.3 TRACTOR (CONT'D)
Travel Speed:
Forward ................................................................................ 0-10 MPH
Reverse ................................................................................. 0-5 MPH
3.4 CUTTER DECK
Type: .......................................................................................... Floating, Adjustable, Anti-scalping, Hybrid Design Combines
Out-front and Belly-mount Designs
Construction: ............................................................................. 10-gauge steel reinforced with 7-gauge 3/16") Support Plate.
7-gauge 3/16") deck skirt with 3/8" front plate.
True Cutting Width: .................................................................. 52" 132.0 cm), 61: 155.0 cm)
Cutting Height Adjustment: ...................................................... Foot Operated Lever Adjustment from Operator's Seat, 1.00" to
6.00" in 1/2"increments
Cutter Blades: ............................................................................ .204 Thick, Milled Edge, 5150 Alloy Steel
SMT 52: Three 3) 18" blades
SMT 61: Three 3) 21" blades
Blade Engagement: .................................................................. Electric Blade Engagement Clutch with Control Panel Switch
Connected to the Cutter Deck Gearbox through a Drive Shaft.
Discharge Opening: .................................................................. Extra Wide 11.5" Discharge Opening with Spring Loaded
Discharge Chute
Caster Wheels: ........................................................................... 13x 5.00 Four-Ply
Spindles: .................................................................................... Heavy-duty 1-1/8" Top Dimension Spindle Shaft, Cast Housing,
Taper Roller Bearing, Low Maintenance with Top Access Grease
Fitting and Grease Overfill Relief Poppet
Spindle Pulleys: ......................................................................... Cast-iron with Easily Removed Taper Hubs
Cutter Deck Belts: ..................................................................... B-section with Kevlar Cord. Self-adjusting, Self-tightening
SMT52 ................................................................................. Scag Part Number - 481557
SMT61 ................................................................................. Scag Part Number - 481558
Electric Clutch Type .................................................................. Warner Mag Stop Electric Clutch
Drive Shaft ................................................................................ Quick-disconnect Shaft With Two High Speed U-Joints
3.6 HYDRAULIC SYSTEM
Hydraulic Oil Filter ................................................................... 10 Micron Spin-on Element Type
Hydraulic Reservoir ................................................................... Nylon; 6 Quart Capacity
3.7 WEIGHTS AND DIMENSIONS 52" MODEL 61" MODEL
Length ........................................................................................ 76" 79"
Tracking Width ......................................................................... 51" 51"
Overall Width ............................................................................ 62" 72"
Overall Height ........................................................................... 30" 30"
Operating Weight ...................................................................... 1160# 1200#
Section 3
3.8 PRODUCTIVITY
The following chart will aid you in determining how many acres your Scag mower will cut per day.
The chart is an estimate based on 8 hours per day cutting time at 4 MPH with an allowance for overlap and turns.
Cutting Width: 36" 48" 52" 61" 72"
Acres Per Day: 9.5 12.5 13.5 16 19
-NOTE-
The machine will travel at 10mph for
transport purposes. For best cutting
performance the forward travel speed
should be adjusted depending upon the
cutting conditions.

7
Section 4